Trie树

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <algorithm>
 4 using namespace std;
 5 
 6 #define MAX_CH 26
 7 #define MAX_NODE 1000005
 8 
 9 int nodecnt;
10 
11 struct TrieNode
12 {
13     int cnt;
14     TrieNode *p[MAX_CH];
15     void init()
16     {
17         cnt = 0;
18         for(int i=0; i<MAX_CH; ++i) p[i] = NULL;
19     }
20     int query(char *s)
21     {
22         int idx = s[0]-‘a‘;
23         if(p[idx]!=NULL)
24         {
25             if(s[1]==‘\0‘) return p[idx]->cnt;
26             else return p[idx]->query(s+1);
27         }
28         else
29         {
30             return 0;
31         }
32     }
33 }t_node[MAX_NODE];
34 
35 struct Trie
36 {
37     TrieNode *rt;
38     void init()
39     {
40         rt = &t_node[0];
41         rt->init();
42         nodecnt = 1;
43     }
44     void insert(char *s)
45     {    
46         TrieNode *now = rt;    
47         for(int i=0; s[i]; ++i)
48         {
49             int idx = s[i]-‘a‘;
50             if(now->p[idx]==NULL)
51             {
52                 now->p[idx] = &t_node[nodecnt++];
53                 now->p[idx]->init();
54             }
55             ++(now->p[idx]->cnt);
56             now = now->p[idx];
57         }
58     }
59     int query(char *s)
60     {
61         return rt->query(s);
62     }
63 }trie;
64 
65 int main()
66 {
67     int n, m;
68     char s[20];
69     while(scanf("%d", &n)!=EOF)
70     {
71         trie.init();
72             
73         while(n--)
74         {
75             scanf("%s", s);
76             trie.insert(s);
77         }
78         
79         scanf("%d", &m);
80         while(m--)
81         {
82             scanf("%s", s);
83             printf("%d\n", trie.query(s));
84         }
85     }    
86     return 0;
87 }